Particle Shielding for Human Spaceflight: Electrostatic Potential Effects on the Störmer Magnetic Dipole Exclusion Region

A basic hybrid radiation shield concept, consisting of both a monopole positive electrostatic potential barrier and a current-carrying superconducting solenoid, was predicted to provide a more effective method of shielding a habitable torus region than a solenoid acting alone. A randomized position and velocity vector simulation of equal-energy iron ions using a Lagrangian reference frame was performed on the exact magnetic field integral for the solenoid and a discrete summation electrostatic field for a toroidal monopole array approximating a potential surface. Each particle is injected at a specific energy (100, 150 MeV and 1 GeV). Two cases were evaluated at each particle energy modeling 2x104 particles. The first case studied effects from only the magnetic dipole field (1.1x1013 A m2); the second case evaluated phenomena from a combined magnetic dipole field and electrostatic potential (20 MV). The toroidal electrostatic potential’s influence on the size and shape of the Störmer magnetic dipole exclusion region was examined as the main evaluating criterion against the pure magnetic field results. It was shown that the electrostatic potential influences the size of the Störmer dipole exclusion region, and the ratio of particle energy to electrostatic potential is significant in determining the amount increased. It was found that a low particle energy to electrostatic potential ratio of 5:1 increases Störmer area approximately by a factor of 2.